The ICatRegister interface provides methods for registering and unregistering component category information in the Registry. This includes both the human-readable names of categories and the categories implemented/required by a given component or class.

When to Implement

There is no need to implement this interface. The Component Category Manager, a system-provided COM object that can be instantiated by using CoCreateInstance, implements ICatRegister.

When to Use

The owner of a category uses this interface to register or unregister the human-readable names. The owner of a component uses this interface to add or remove categories implemented or required by this component.

Methods in Vtable Order

IUnknown Methods                       Description                                    
                                                                                      

QueryInterface                         

Returns pointers to supported interfaces.      
                                                                                      

AddRef                                 Increments reference count.                    
                                                                                      

Release                                Decrements reference count.                    
                                                                                      

ICatRegister Methods                   Description                                    
                                                                                      

RegisterCategories                     

Registers one or more component categories.    
                                                                                      

UnRegisterCategories                   Removes the registration of one or more        
                                       component categories.                           
                                                                                      

RegisterClassImplCategories            Registers the class as implementing one or more 
                                       component categories.                           
                                                                                      

UnRegisterClassImplCategories          Removes one or more implemented category       
                                       identifiers from a class.                       
                                                                                      

RegisterClassReqCategories             Registers the class as requiring one or more   
                                       component categories.                           
                                                                                      

UnRegisterClassReqCategories           Removes one or more required category          
                                       identifiers from a class.